The present disclosure generally relates to railroad maintenance machinery, and more particularly relates to machinery used for removing and inserting railroad ties.
Tie replacing machines are typically built to roll on a railroad track and stop at a rail tie that needs repair or replacement. Most machines have a telescoping boom member that positions a gripping mechanism normally relative to the track and adjacent to an end of the rail tie to remove it. The gripping mechanism typically has vice-like jaws that clamp onto the end of the rail tie. As the telescoping boom member extends normally away from the track, and the jaws pull the tie from under the railroad track. A reverse operation is used to insert a new tie under the track. An exemplary tie replacing machine is described in commonly assigned U.S. Pat. No. 6,463,858, which is incorporated by reference.
While these conventional machines are able to remove and replace the railroad ties, the machines are subject to disadvantages. One disadvantage is that each gripping mechanism includes a housing having a pair of jaws, each attached as a unit to a corresponding side of the housing such that the jaws grasp the rail tie for its removal or insertion. In use, the jaws wear unevenly. Because they are unitary, when only one end of the jaw is worn, the entire unit must be replaced. Also, the conventional nuts and bolts retaining the jaws to the corresponding arm become severely worn during use. As a result, replacement of the jaws often requires significant efforts by maintenance personnel.
Accordingly, there is a need for developing an improved tie gripping mechanism.